Sky-high radiation known from get-go

Workers at the Fukushima No. 1 plant came to terms with the possibility of high radiation levels soon after the nuclear crisis started in March 2011, teleconference video footage by Tokyo Electric Power Co. shows.

Staff apparently quickly perceived that being too concerned about radiation exposure would impede containing the crisis at the plant. According to the footage, it was reported on the night of March 14 that the level of gamma radiation at the main gate of the plant had reached 3.2 millisieverts per hour.

Masao Yoshida, then manager of the plant, commented that the reading was equal to some 3,000 microsieverts.

Sakae Muto, then executive vice president of Tepco, who was at the company’s headquarters in Tokyo at the time, said, “The reading is the highest ever, isn’t it?”

But Yoshida brushed aside Muto’s concerns, saying: “We have already seen readings like 1,500 and 2,000 microsieverts. Now, we don’t care about (radiation levels) at all.”

Days later, on the morning of March 22, the plant’s medical team said emergency examinations would be carried out on workers whose cumulative radiation doses had topped 100 millisieverts, as ordered by the health ministry.